Cosmetic devices

ABSTRACT

The present invention relates to pre-formed devices for delivering benefit agents to the skin, hair or nails. The devices are patches or masks for cosmetic or therapeutic use and comprise a unilamellar, solid gel sheet having at least one surface at least partially coated with a discrete coating composition comprising at least one benefit agent for the skin, hair or nails. The invention also encompasses methods of producing and using such devices. The coating composition allows more efficient delivery of benefit agents to the skin than previously known devices and/or affords greater formulation flexibility.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of application Ser. No. 10/268,556,filed Oct. 10, 2002 which claims priority to International ApplicationNo. PCT/US00/09694, filed Apr. 12, 2000.

TECHNICAL FIELD

The present invention relates to pre-formed devices in the form of a gelsheet for delivering benefit agents to the skin, hair or nails. Moreparticularly the invention relates to gel sheets having a coatingcomposition on at least one surface. The coating composition comprisesat least one skin benefit agent and allows more efficient delivery ofbenefit agents to the skin than previously known, uncoated sheets and/oraffords greater formulation flexibility.

BACKGROUND OF THE INVENTION

The benefits of using a patch or mask device comprising a polymeric gelforming agent instead of creams and lotions and the like, tocosmetically treat the skin, hair or nails, or to promote the healing ofburns or wounds have been recognised in the art. A variety of cosmeticpatches or devices are commercially marketed or described as beinguseful for the delivery of skin care actives such as vitamins, anti-acneactives, moisturisers and the like. Patches have also been described inthe literature and marketed in the medical field as a useful means forthe transdermal administration of drugs.

However, many patches or similar devices suffer drawbacks in theirphysical product forms resulting in undesirable in-use characteristicsas perceived by the consumer or wearer. For example, some patches ordevices may be too wet or sticky, as the gel forming agents comprisingthe patch or device do not form a solid gel structure and as a result,the patches or devices are difficult to handle and apply to the skin.Others are strongly adhesive, tight and uncomfortable to wear andremove, and many patches do not provide an effective release andpenetration of benefit agents. Further, some patches or devices are toodry or inflexible and therefore do not conform well to the contours ofthe surface to which they are applied.

WO 97/17944 discloses structured cosmetic gel formulations which areoptionally enriched with water-soluble or water-dispersible activeingredients. The optional ingredients are incorporated during gelformation.

Several applications disclose active agents, such as vitamins,incorporated into pressure-sensitive adhesive devices. GB-A-2 265 086,for example, describes skin whitening patches in which skin whiteningagents and other ingredients, such as permeation enhancers and glycerin,are formulated into an adhesive layer attached to an impermeable backingU.S. Pat. No. 5,785,978 teaches the incorporation of vitamins,especially vitamin C, in powder form into an adhesive layer which alsohas an impermeable backing. U.S. Pat. No. 5,965,154 also relates to theincorporation of active ingredients such as powdered vitamin C into anadhesive layer. WO 98/42303 is yet a further publication dealing withthe incorporation of active ingredients such as powdered vitamin C intoa product which has a substrate and a layer comprising an adhesivepolymer. In this application the function of the adhesive layer is tostrip away keratotic plugs. Its substrate layer is preferablynon-occlusive. U.S. Pat. No. 5,723,138 teaches products in whichcosmetic ingredients, for preventing removing or alleviating wrinkles,are incorporated into adhesives and applied to a tape.

EP-A-161 681 discloses polysaccharide gel plates for use as poultices.The plates may comprise medical components such as skin stimulants,antiphlogistics, analgesics and antibiotics. The medical component canbe incorporated into the plate as the plate is formed or subsequentlycoated or impregnated with a solution or dispersion of the component. Inthe case of subsequent addition of the medical component it is taughtthat the intermediate gel plate product is dried to give it a highabsorbency for the medical component.

NZ 329525 describes a method of treating the skin comprising applying acosmetic preparation to the skin and then applying a dressing over thetop. JP 11-130625 describes an acrylic gel based sheet pack fortreatment of facial wrinkles Optionally, a separate lotion can beapplied to the face before the pack is applied. Likewise, commercialproducts are sold in Japan, such as Sofina Seraty Wrinkle Device EyePatch from Kao Corporation, which recommend pre-treatment of the facewith a gel or lotion before the sheet is applied to the face. Suchproducts may be sold as kits and require separate application of agel/lotion and a sheet.

Co-pending PCT application no. PCT/US99/15202 discloses gel patcheswhich comprise cosmetic agents dispersed within them but which exhibit amoderate amount of syneresis so that an exudate will be released ontothe surface.

It has now been found that the efficacy of a gel sheet in deliveringbenefit agents to the skin, hair or nails can be improved by coating apre-formed gel sheet with a discrete, separate coating compositioncomprising at least one skin benefit agent. Furthermore, this structurefor a gel device allows greater formulation flexibility e.g. by allowingthe incorporation of benefit agents, such as powders, which would nototherwise migrate out of a gel matrix, or by allowing drier gels whichare easier to handle or more pleasant to the touch where they arenon-coated.

The gel devices herein are patches or masks for cosmetic or therapeuticapplication.

SUMMARY OF THE INVENTION

The present invention relates to a pre-formed device for deliveringbenefit agents to the skin, hair or nails, the device comprising a solidgel sheet having opposed first and second surfaces, wherein the gelsheet comprises one or more gelling agents and at least 10%dermatologically acceptable hydrophilic solvent, characterised in thatthe first surface is at least partially coated with a discrete coatingcomposition comprising at least one benefit agent for the skin, hair ornails. Methods of manufacture and use of the coated devices are alsoprovided.

The use of a coating composition allows more efficient delivery ofbenefit agents to the skin than previously known devices and affordsgreater formulation flexibility. The pre-formed, coated devices of thepresent invention provide excellent hydration and moisturisationbenefits upon topical application as well as chronic benefits byimproved delivery of topically effective actives. Further, thepre-formed devices of the present invention have excellent mechanicaland optical properties, having a high strength structure which isflexible, elastic and optically clear, thus providing desirable in-usecharacteristics such as unobtrusiveness and conformability. The coatingcomposition allows more efficient delivery of benefit agents to the skinthan previously known devices and/or affords greater formulationflexibility.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a device according to the invention, thegel sheet of the device is textured on first and second surfaces and acoating has been applied to the first surface.

FIG. 2 is a schematic view of a set up for measuring device flexibility.

DETAILED DESCRIPTION OF THE INVENTION

The pre-formed devices of the present invention comprise a solid gelsheet and a discrete coating composition. All levels and ratios of gelsheet components are by weight of the gel sheet, and all levels andratios of coating composition components are by weight of the coatingcomposition, unless otherwise indicated. All measurements herein aremade at 25° C., unless otherwise specified. The invention particularlyrelates to pre-formed devices which are manufactured on an industrialscale and packaged in protective wrappers, for shipment and retail sale.The devices are used for delivering benefit agents to the skin, hair ornails, preferably the skin or nails, most preferably the skin, inparticular facial skin.

The term “pre-formed” as used herein, means that the device ismanufactured into a form having a predetermined thickness, shape andsize, wherein the device may be removed from any associated packagingand placed or draped onto the target surface by the fingers withoutfurther preparative steps by the user.

The term “gel sheet”, as used herein, means a patch or mask, forcosmetic or medical application, which is a continuous, uni-, bi-, ormulti-lamellar sheet, the shape of which is pre-determined according tothe specific area of skin, hair or nails to be treated, masks beingdesigned to cover the facial area and having apertures for the eyes,nose or mouth. Preferred gel sheets are unilamellar, by which is meantthat they comprise a single layer.

“Solid” as used in reference to gel sheets herein, means that the sheetsubstantially retains its shape at 25° C. when lying on a flat surface.The sheet may nevertheless flex or be deformed when applied to an unevensurface or if impressed.

The term “hydrophilic” as used in reference to solvents herein, meansthat the solvent is miscible with water, at least in a solvent to waterratio of 1 to 10, preferably 1 to 5.

The term “water-soluble” as used herein, means the ability of a gellablepolymeric gel forming agent to dissolve in an aqueous solution either atroom temperature or upon heating thereby forming a continuous phase.

The term “syneresis” as used herein, means the process whereby a gelcontracts on standing with the exudation of liquid. Without beinglimited by theory, it is believed that gel compositions herein form3-dimensional matrices which bind or encapsulate other ingredients ofthe composition. Syneresis is believed to involve a spontaneousseparation of an initial homogeneous system into a coherent gel phaseand a liquid. The exuded liquid is a solution whose composition dependsupon that of the original gel.

The term “polysaccharide” herein means a naturally occurring orsynthetically produced, linear, branched or cross-linked polymer ofmonosaccharide units, which swells when dispersed in water at lowconcentrations and thickens the aqueous phase.

The term “non-planar topography” refers to at least two adjacentdelineated areas of a surface of the device, or of an auxiliary surfacefor applying a non-planar topography to the device, lying in differentplanes such that the surface is textured. The texture can be rough,undulating or stepped and can be regular or irregular.

The term “periodicity” as used herein, means a pattern of repeatingunits and is a measure of the distance between the start point and endpoint of a repeat unit of pattern.

Gel Sheets

The pre-formed devices of the present invention comprise a solid gelsheet. The sheet provides the primary structure and shape to the device,allowing it to be handled and to suit treatment of a specific targetarea of the skin, hair or nails. It can also act as a reservoir or as adelivery vehicle for benefit agents and, by virtue of evaporation of asolvent from the sheet, provide a cooling action to the device duringuse.

The gel sheets have a size and shape adapted to conform to a desiredtarget area which could be the nails or cuticles, the hair or scalp, ahuman face or part thereof, legs, hands, arms, feet, or human torso.They are generally flat in appearance, having opposed first and secondsurfaces. Devices according to the present invention are generally of asize such that each surface has an area of from about 0.25 cm² to about1,000 cm², preferably from about 1 cm² to about 100 cm². Surface arearefers to that of a flat plane having the same boundary as the surfacei.e. ignoring any surface texturing present. Generally, at least onesurface dimension of the device, preferably both, is greater than thedepth of the device, with preferred ratios of surface dimension(s) todepth of the device being in the range of from about 2:1 to about 100:1,more preferably from about 5:1 to about 50:1. The term “surfacedimension” as used herein, means a dimension in the x- or y-axes, depthbeing measured along the z-axis.

The exact size and shape will depend upon the intended use and productcharacteristics. The devices herein can be, for example, square,circular, semicircular, rectangular, oval, rings, crescents, teardropsor other more complex shapes which may be composites of these. Devicesshaped to fit the face have a surface area ranging from about 0.25 cm²to about 500 cm², preferably from about 1 cm² to about 400 cm². Thedevices generally have an average thickness of from about 0.5 mm toabout 20 mm, preferably from about 0.7 mm to about 5 mm. Preferreddevices have a thickened rim which is from about 0.1 to about 1.5 mm,preferably from about 0.2 to about 1 mm thicker than the central portionof the patch. It has been found that the thickened rim considerablyincreases patch strength towards handling without significantly reducingits flexibility.

Either or both of the first and second surfaces of the gel sheet canhave a non-planar topography. The non-planar topography can begeneralised across the surface of the patch, such as a surface texture,or can be a localised discontinuity such as a thickened peripheral rim.Preferably at least the first surface is textured, having a texturedefined by R_(a) of greater than about 10 μm. The texturing can have apattern which is regular or irregular. The preferred pattern issinusoidal, saw tooth or conical with a periodicity of from about 0.1 mmto about 10 mm, preferably from about 0.5 mm to about 5 mm. Thetexturing of the first surface is useful for improving the adhesion ofthe coating composition to the gel sheet. Texturing of the secondsurface, which in use will be distal to the skin, nails or hair, isuseful for reducing surface shine, making the device less obtrusivewhilst being worn. A thickened rim can provide some additional integrityto the device, enabling it to be handled more easily without tearing.Preferably, a non-planar topography, being either a textured surface orat least two delineated regions simultaneously not having the same meanthickness or both, is applied to both first and second surfaces of thegel sheet.

The gel sheets comprise as essential components, one or more gellingagents and at least 10% dermatologically acceptable hydrophilic solvent.They can also optionally comprise a variety of other ingredients, inparticular benefit agents and auxiliary additives which are described inmore detail below following the general description of the coatingcomposition. The gelling agents and hydrophilic solvent will now bedescribed in more detail.

Gelling Agents

In general, the gel sheets of the present invention comprise less than70%, preferably less than 50%, more preferably less than 30% andespecially less than 10% by total weight of a gelling agent. Many typesof gelling agents, or gellants, are known in the art, includingpolymeric gellants and particulate based gellants such as various typesof clays or other silicate based materials. Highly preferred herein arepolymeric gelling agents from the point of view of the structure thatthey provide to the gels.

Polymeric gellants for use herein may be naturally or syntheticallyderived and can be self-gelling or may only form gels in combinationwith other substances. They may be physically or chemically crosslinked. Some gelling agents form gels in combination with substancessuch as sugar, alcohol, or mono- or multi-valent salts. Mono- ormulti-valent salts may additionally act as gel strengthening agentsimparting added strength to the gel sheets herein. Suitable cations forsuch salts can be selected from potassium, sodium, ammonium, zinc,aluminium, calcium and magnesium ions, or mixtures thereof. Suitableanions associated with the aforementioned cations may be selected fromchloride, citrates, sulphate, carbonate, borate and phosphate anions, ormixtures thereof.

Physical cross linking refers to polymers having cross links which arenot chemical covalent bonds but are of a physical nature such that thereare areas in the device having high crystallinity or areas having a highglass transition temperature. Chemical cross linking refers to polymerswhich are linked by chemical bonds. Preferably, the polymer ischemically cross linked by radiation techniques such as thermal-, Ebeam-, UV-, gamma or micro-wave radiation. In addition when chemicalcross links are formed in the system, a polyfunctional cross linkerand/or a free radical initiator may be present in the premix to initiatethe cross linking upon irradiation. Such components can be present inquantities of up to 5% by weight.

Polymeric gellants are water soluble or water insoluble, preferably theyare water soluble. Alternatively, they can be non-water solublepolymeric gellants comprising silicone materials e.g. organopolysiloxaneresins, or block co-polymer thermoplastic elastomers. A more detaileddescription of water insoluble polymeric gellants can be found inco-pending PCT application no. PCT/US99/15201 incorporated herein byreference in its entirety.

The water-soluble polymeric gellants for use in the present inventionare selected from synthetic or natural polymers, and mixtures thereof.In general, the pre-formed, gel sheets of the present invention compriseless than 50%, more preferably less than 30% and especially less than20% by total weight of a water-soluble polymeric gellant. Suitablesynthetic polymers for use herein include non-ionic water-solublepolymers, acrylic acid based polymers, cellulose derivatives, andmixtures thereof. Many materials of this type are known in the art andexemplary materials are to be found in co-pending PCT application no.PCT/US99/15201.

A particularly preferred synthetic polymer system is disclosed in WO00/06215, incorporated herein by reference, which describes a productsuitable for attaching biomedical devices to the skin. In particular thedocument discloses a bioadhesive, hydrogel composition comprising anaqueous plasticiser, a polymer of one or more monomers comprising ahydrophilic unsaturated water soluble acrylamido monomer, particularlyNaAMPS, and a hydrophobic polymer, such as an ethylene/vinyl acetatecopolymer.

Preferred polymers for use herein are natural polymers, includinggelatin, poly-saccharides, and mixtures thereof. Preferred arepolysaccharides. The polysaccharides for use in the devices herein arepreferably selected from red seaweed polysaccharides; glucomannans;galactomannans; fermentation polysaccharides, or derivatives thereof;brown seaweed polysaccharides; extracts of marine invertebrates; starch,or derivatives thereof; natural fruit extracts; plant fiber derivatives;kelp; natural plant exudates; and resinous gums; or mixtures thereof.When the gel sheets herein contain one or more polysaccharides as thewater-soluble polymeric gelling agent(s), the sheets generally compriseless than 10%, preferably less than 7% and more preferably less than 5%by total dry weight of a polysaccharide or mixtures thereof. It isbelieved that low total polysaccharide levels impart an open gelstructure such that the other components of the gel are not as tightlybound within the gel network and are freely available for diffusion.

When gelatin is used in the devices herein, a high-molecular weightgelatin is combined with a low-molecular weight one to control thesolubility. A gelatin having a low molecular weight of 20,000 or less ispoor in gelling ability.

Brown seaweed polysaccharides are isolated by extraction from variousspecies of Phaebophyceae. Suitable brown seaweed polysaccharides for useherein include algin, alginic acid, ammonium alginate, calcium alginate,potassium alginate, sodium alginate, propylene glycol alginate, andmixtures thereof.

Red seaweed polysaccharides are isolated from marine plant speciesbelonging to the class of Rhodophyceae. Red seaweed polysaccharidesprovide mechanical strength to an aqueous gel. Suitable red seaweedpolysaccharides for use in the present invention include agar known inthe industry under the (CTFA) trade designation as agar agar flakederived from various Gelidium plant species or closely related red algaecommercially available as “Agar Agar 100” or “Agar Agar 150” from TICGums (Belcamp, Md., USA) or “Agar Agar K-100” from Gumix InternationalInc. (Fort Lee, N.J., USA); agarose commercially available as “SeaPlaque®” from FMC (Philadelphia, Pa., USA) and “Agarose Type 1-b” fromSigma-Aldrich Co. Ltd. (Poole, UK); carrageenan, comprising thefractions lambda-, iota- and kappa- which are the water extractsobtained from various members of the Gigartinaceae or Solieriaceaefamilies, known in the industry under the (CTFA) trade designation aschondrus, commercially available as “Gelcarin® LA”, “Seakem® 3/LCM”, or“Viscarin® XLV”, all from FMC (Philadelphia, Pa., USA); and furcellarancommercially available from Gum Technology Corporation (Tucson, Ariz.,USA) and Continental Colloids Inc. (Chicago, Ill., USA), or mixturesthereof. Preferably, the red seaweed polysaccharide for use herein isselected from agar, agarose, kappa-carrageenan and furcellaran, ormixtures thereof.

Glucomannans are polysaccharides which comprise an essentially linearbackbone of glucose and mannose residues. Glucomannans have short sidebranches attached to the linear backbone and acetyl groups are randomlypresent at the C-6 position of a sugar unit. The acetyl groups aregenerally found on one per six sugar units to one per twenty sugarunits. Suitable glucomannans or derivatives thereof for use herein havea ratio of mannose to glucose of from about 0.2 to about 3. Preferredglucomannans for use herein include konjac mannan, which is the genericname for the flour formed from grinding the tuber root of theAmorphophallus konjac plant (elephant yam), commercially available underthe trade name “Nutricol® konjac flour” from FMC (Philadelphia, Pa.,USA); and deacetylated konjac mannan; or mixtures thereof.

Galactomannans are vegetable reserve polysaccharides which occur in theendosperm cells of numerous seeds of Leguminosae. The collective term“galactomannan” comprises all polysaccharides which are built up ofgalactose and mannose residues. Galactomannans comprise a linearbackbone of (1→4)-linked β-D-mannopyranosyl units. To these rings areattached as branches, isolated galactopyranose residues byα-(1,6)-glucoside bonds. Galactomannans may in addition also containminor amounts of other sugar residues. Suitable galactomannans for useherein are fenugreek gum; lucern; clover; locust bean gum known forexample in the industry under the (CTFA) trade designation as carob beangum, commercially available as “Seagul L” from FMC (Philadelphia, Pa.,USA); tara gum commercially available from Starlight Products (Rouen,France) or Bunge Foods (Atlanta, Ga., USA); guar gum derived from theground endosperms of Cyamopsis tetragonolobus, commercially available as“Burtonite V7E” from TIC Gums (Belcamp, Md., USA), “Jaguar C” fromRhone-Poulenc (Marietta, Ga., USA), or “Supercol” from Aqualon(Wilmington, Del., USA); and cassia gum commercially available fromStarlight Products (Rouen, France), or mixtures thereof. Preferably, thegalactomannans for use herein have an average one of every 1 to about 5mannosyl units substituted with a (1→6)-linked-α-D-galactopyranosyl unitand are selected from guar gum, locust bean gum and cassia gum, ormixtures thereof.

Fermentation polysaccharides are polysaccharides which are commerciallyproduced by the fermentation of micro-organisms in a medium containing acarbon and nitrogen source, buffering agent, and trace elements.Suitable fermentation poly-saccharides or derivatives thereof, for usein the present invention include gellan gum known in the industry underthe (CTFA) trade designation as gum gellan, a high molecular weighthetero polysaccharide gum produced by a pure-culture fermentation of acarbohydrate with Pseudomonas elodea, commercially available as“Kelcogel” from Kelco (San Diego, Calif., USA); xanthan gum which is ahigh molecular weight hetero polysaccharide gum produced by apure-culture fermentation of a carbohydrate with Xanthomonas campestris,known in the industry under the (CTFA) trade designation as xanthan,commercially available for example as “Keltrol CG1000/BT/F/GM/RD/SF/T/TF”, from Calgon (Pittsburgh, Pa., USA), or“Kelzan” from Kelco (San Diego, Calif., USA); natto gum; pullulan;rhamsan gum; curdlan; succinoglycan; welan gum; dextran, commerciallyavailable as “Sephadex G-25” from Pharmacia Fine Chemicals (Piscataway,N.J., USA) and derivatives thereof; and sclerotium gum, commerciallyavailable as “Amigel” from Alban Muller International (Montreil,France), or mixtures thereof. Preferred fermentation polysaccharides orderivatives thereof are selected from gellan gum and xanthan gum, ormixtures thereof. More preferably the fermentation polysaccharide orderivative thereof is xanthan gum.

Extracts of marine invertebrates can also be used. Polysaccharidesderived from marine invertebrates, specifically the exoskeleton of suchinvertebrates, consist chiefly of N-acetyl-D-glucosamine residues.Examples of such polysaccharides suitable for use herein includechitosan, commercially available for example as “Marine Dew” fromAjinomoto (Teakneck, N.J., USA); and hydroxypropyl chitosan commerciallyavailable for example as “HPCH Liquid” from Ichimaru Pharcos (YamagataGun Gifu-Pref, Japan) and derivatives; or mixtures thereof.

Starches are polysaccharides which consist of various proportions of twoglucose polymers, amylose and amylopectin. Suitable materials for useherein include starch, amylopectin and dextrin, commercially availableas “Nadex 360” from National Starch (Bridgewater, N.J., USA), andderivatives or mixtures thereof. Examples of natural fruit extractssuitable for use herein include pectin, arabian and mixtures thereof. Asuitable example of a plant fibre derivative for use herein iscellulose. Suitable polysaccharides obtained from natural plant exudatesfor use herein include karaya, tragacanth, arabic, tamarind, and ghattygums, or mixtures thereof. Examples of resinous gums suitable for useherein include shellac gum, which is obtained from the resinoussecretion of the insect Laccifer (Tachardia) lacca, damar gum; copal gumand rosin gum; or mixtures thereof.

Preferably, the pre-formed, unilamellar gel sheets herein comprise amixture of water-soluble polymeric gel forming agents. The mixture isselected from one or more non-ionic water-soluble polymers; one or moreacrylic acid based polymers or derivatives thereof; one or morepolysaccharides; and mixtures thereof. For example, a preferredwater-soluble polymeric gel forming agent mixture herein may comprise apolysaccharide and a non-ionic water-soluble polymer or, alternatively,it may comprise two poly-saccharides. More preferably, the water-solublepolymeric gel forming agent is a polysaccharide mixture, wherein thepolysaccharide mixture comprises (1) at least one red seaweedpolysaccharide; brown seaweed polysaccharide; or mixtures thereof; and(2) at least one fermentation polysaccharide; galactomannan;glucomannan; natural plant exudate; or natural fruit extract; andderivatives or mixtures thereof. Even more preferably, the water-solublepolymeric gel forming agent of the devices of the present invention is apolysaccharide mixture comprising (1) at least one red seaweedpolysaccharide; and (2) at least one fermentation polysaccharide;glucomannan; or galactomannan; and derivatives or mixtures thereof.

In a preferred embodiment, the water-soluble polymeric gel forming agentof the present invention is a polysaccharide mixture, comprising a redseaweed polysaccharide and a glucomannan or a galactomannan. The ratioof red seaweed polysaccharide to glucomannan or galactomannan in thepolysaccharide mixture is preferably from about 20:1 to about 1:5 andmore preferably from about 10:1 to about 1:2.

When the polymeric gel forming agents are natural in origin, the gelsundergo syneresis, as herein before defined, to some degree. Syneresisprovides one mechanism for the delivery of a benefit agent to a targetarea. The liquid layer exuded onto the surface of the coherent gel phaseis readily available for diffusion, facilitating a short wear time ofthe device.

Hydrophilic Solvent

The gel sheets of the devices of the invention comprise at least 10%dermatologically acceptable, hydrophilic solvent. The solvent acts as aplasticiser or softener for the device, thus providing the desiredmechanical properties, particularly flexibility. As used herein, adermatologically acceptable, hydrophilic solvent is one which can beused in a sheet to be applied against the skin without causingirritation and which is miscible with water, at least in a solvent towater ratio of 1 to 10, preferably 1 to 5. A highly preferredhydrophilic solvent is water itself. Other suitable hydrophilic solventsinclude ethanol, propylene glycol, glycerine, sorbitol; polyethyleneglycols of MW less than 30,000, preferably less than 10,000; andpolypropylene glycols of MW less than 5,000, preferably less than 1,000;which can be used alone, in admixture or, preferably, in admixture withwater. If necessary the solvents may be warmed to liquefy them. The useof the hydrophilic solvent not only helps to provide the desiredmechanical properties to the device but can assist in diffusion ofbenefit agents to the skin and, by evaporation from the gel sheet, canalso provide cooling, making the device more comfortable to wear.Preferred in this latter respect are solvents which are liquid at 25°C., more preferably less than 20% by weight of a solvent mixture iscomprised of solvents which are solid at 25° C. Particularly preferredhydrophilic solvents are water, ethanol, propylene glycol and mixturesthereof. The total hydrophilic solvent content of the gel sheet ispreferably from about 15% to about 99%, more preferably from about 20%to about 95%, and yet more preferably from about 50% to about 90% byweight of the gel sheet. Preferred gel sheets comprise more than about10% water, more preferably more than about 30% water.

Coating Compositions

In the pre-formed device of the present invention, the first surface isat least partially coated with a discrete coating composition comprisingat least one benefit agent for the skin, hair or nails. By “discrete”coating composition is meant one that is applied to the gel sheet as adistinctly different composition, in particular one having a differentchemical constitution which is separately prepared from the gel sheetand is laid down as a separate layer, before, after or at the same timeas the formation of the gel sheet. The coating composition allows moreefficient delivery of benefit agents to the skin and affords greaterformulation flexibility.

Use of the singular of “coating composition” herein is not intended toinclude two or more coating compositions applied to different parts ofthe same gel sheet. In particular it is envisaged that for a device suchas a face mask, a composition suitable for oily skin may be applied to aportion of the device intended to contact the so-called ‘T-zone’ and adifferent composition suitable for dry skin may be applied to anotherarea of the mask intended to contact the cheeks for example. Moregenerally the coating may comprise two or more areas of differentcomposition to suit different areas of the skin hair or nails.Alternatively the coating may be applied in two or more layers ofdifferent composition to provide for sequential release of ingredients.Preferably however, a single uniform composition is applied. Referencesherein to ‘coating composition’ are intended to cover either uniform orheterogeneous compositions. Generally, the coating composition covers atleast about 20%, preferably at least about 50%, more preferably at leastabout 75% of the area of the first surface. The coating composition canassist in adhering the patch to the skin, in which case it can beappropriate for the entire first surface to be coated with the coatingcomposition. Alternately, there can be an area of the first surface,such as a peripheral rim, optionally with some areas in the centralportion of the first surface, which is left uncoated, for the purpose ofeasier or less messy handling of the device or for assisting adhesion ofthe device to a target area of the skin, hair or nails.

The coating composition can be solid, such as a powder, or a liquid,including gels. Preferably the coating composition is a liquid, andparticularly a liquid having a viscosity greater than about 1000 mPa·s,preferably greater than about 5,000 mPa·s, more preferably greater thanabout 7,000 mPa·s as measured on a Brookfield viscometer using aheliopath T-bar C spindle at 5 rpm.

Liquid coating compositions can be aqueous solutions, including gels, oremulsions such as oil-in-water emulsions, water-in-oil emulsions ormultiple emulsions having aqueous or oily external phases. In preferredembodiments herein the coating composition is an oil-in-water emulsionhaving one or more internal oil phases which can include a silicone oilphase.

The weight ratio of the coating to the gel sheet is generally in therange from about 1:100 to about 2:1, preferably from about 1:25 to about1:1, more preferably from about 1:15 to about 1:2. Preferred dosagerates of the coating compositions on the gel patch can alternatively beexpressed as from about 0.001 to about 0.2 gcm⁻², preferably from about0.005 to about 0.05 gcm⁻².

The coating composition comprises at least one benefit agent for theskin, hair or nails. Such benefit agents can be unique to the coatingcomposition or the same as benefit agents which may be present in thegel sheet. Preferably, the gel sheet and the coating composition eachcomprise at least one skin benefit agent in common. In this way, whilstthe coating composition can rapidly provide a benefit agent to thetarget area, the gel sheet can act as a reservoir for the benefit agentor inhibit the gel sheet from absorbing the benefit agent from thecoating composition.

Benefit Agents

An essential characteristic of the pre-formed device of the presentinvention is that the coating composition comprises at least one benefitagent for the skin hair, or nails. The solid gel sheet preferably alsocomprises one or more of such benefit agents. The term “benefit agent”as used herein, means an active ingredient which provides a cosmeticand/or therapeutic effect to the area of application. Included in thisdefinition of benefit agents are the categories listed below as well as,for example, vitamins, and humectants.

The benefit agents are used in a safe and effective amount, by which ismeant an amount high enough to deliver the desired skin, hair or nailbenefit but low enough to avoid serious side effects, at a reasonablebenefit to risk ratio within the scope of sound medical judgement. Theamount by weight of the benefit agent will vary with the specific agent,the ability of the agent to penetrate through the skin or into, or ontothe hair and/or nails, the user's age, the user's health condition, andthe condition of the skin, hair or nails of the user, and other likefactors.

Benefit agents herein include their pharmaceutically-acceptable salts,by which is meant any of the commonly-used salts that are suitable foruse in contact with human tissues without undue toxicity, irritation,incompatibility, allergic response, and the like.

In general, the coating compositions of the present invention comprisefrom about 0.01% to about 60%, preferably from about 0.1% to about 40%and most preferably from about 0.5% to about 30% by weight of thecoating compositions of at least one benefit agent, or mixtures thereof.

The benefit agents useful herein can be categorised by their cosmetic ortherapeutic benefit or their postulated mode of action. However, it isto be understood that they can in some instances provide more than onecosmetic or therapeutic benefit or operate via more than one mode ofaction. Therefore, classifications herein are made for the sake ofconvenience and are not intended to limit the benefit agent to thatparticular application or applications listed. The following exemplarybenefit agents are useful in the device of the present invention. A morecomplete listing of benefit agents can be found in WO98/18444 andco-pending PCT application no. PCT/US99/15202, both of which areincorporated herein by reference.

Anti-Acne Actives: Anti-acne actives can be effective in treating andpreventing acne vulgaris, a chronic disorder of the pilosebaceousfollicles. Preferred anti-acne actives include benzoyl peroxide, lacticacid, 4-methoxysalicylic acid, metronidazole, niacinamide, panthenol,retinoic acid and derivatives thereof, salicylic acid, sulphur,triclosan, zinc oxide, and mixtures thereof.

Emollients: Examples of emollients useful herein include mineral oil,petrolatum, C₇-C₄₀ branched chain hydrocarbons, C₁-C₃₀ alcohol esters ofC₁-C₃₀ carboxylic acids, monoglycerides of C₁-C₃₀ carboxylic acids,C₁-C₃₀ carboxylic acid monoesters and polyesters of sugars, for example,sefa cottonate (sucrose polycottonseedate), polydialkylsiloxanes;silicone gums, resins and elastomers; cyclomethicones having 3 to 9silicon atoms, vegetable oils, hydrogenated vegetable oils and mixturesthereof. Preferred emollients are selected from linear and branchedchain hydrocarbons, sugar polyesters and silicones, especiallydimethicone and dimethiconol.

Non-Steroidal Anti-Inflammatory Actives (NSAIDS): Examples of suitableNSAIDS and their esters for use herein are described in WO98/18444.

Topical Anaesthetics: Examples of suitable topical anaesthetic drugs foruse herein are benzocaine and bupivacaine.

Artificial Tanning Agents and Accelerators: Artificial tanning agentscan help in simulating a natural suntan by increasing melanin in theskin or by producing the appearance of increased melanin in the skin.Non-limiting examples of artificial tanning agents and acceleratorsinclude dihydroxyacetone, glucose tyrosinate and acetyl tyrosine,brazilin, caffeine, coffee extracts, DNA fragments, isobutyl methylxanthine, methyl xanthine, PHOTOTAN (available from LaboratoiresSerobiologiques located in Somerville, N.J.), prostaglandins, teaextracts, theophylline, UNIPERTAN P2002 (available from Unichem, locatedin Chicago, Ill.) and UNIPERTAN P27 (available from Unichem, located inChicago, Ill.); and mixtures thereof.

Antiseptics: Suitable antiseptics for use herein include alcohols,benzoate, sorbic acid, and mixtures thereof.

Anti-microbial and Anti-fungal Actives: Anti-microbial and anti-fungalactives can be effective to prevent the proliferation and growth ofbacteria and fungi. Non-limiting examples of antimicrobial andantifungal actives include ketoconazole, benzoyl peroxide, tetracycline,benzalkonium chloride, benzoic acid and its salts, butyl paraben,cinnamon oil, citronella oil, echinacea, ethyl paraben, GLYDANT PLUS(available from Lonza located in Fairlawn, N.J.), grapefruit seed oil,iodopropynl butyl carbamide lemon balm oil, salicylic acid, sodiummetabisulphite, sodium sulphite, sorbic acid and its salts, and tea treeoil.

Skin Soothing Agents: Skin soothing agents can be effective inpreventing or treating inflammation of the skin. The soothing agentenhances the skin appearance benefits of the present invention, e.g.,such agents contribute to a more uniform and acceptable skin tone orcolour. Examples of skin soothing agents include allantoin, aloe,bisabolol, borage oil, chamomile, evening primrose, panthenol, andtocopherol.

Sunscreening Agents: Sunscreens useful herein include both inorganicsunscreens such as titanium and zinc oxides, as well as the manycommercially available UVA and UVB absorbing organic sunscreens.

Skin Barrier Repair Aids: Skin barrier repair actives are those skincare actives which can help repair and replenish the natural moisturebarrier function of the epidermis. Non-limiting examples of skin barrierrepair aids include ceramides, cholesterol, lanolin, lanolin alcohols,n-acetyl cysteine, n-acetyl-L-serine, niacinamide, nicotinic acid andits esters, nicotinyl alcohol, panthenol, phosphodiesterase inhibitors,trimethyl glycine, tocopheryl nicotinate, and vitamin D3 and analogs orderivatives.

Anti-Wrinkle and Anti-Skin Atrophy Actives: Anti-wrinkle and anti-skinatrophy actives can be effective in replenishing or rejuvenating theepidermal and/or dermal layer. These actives generally provide thesedesirable skin care benefits by promoting or maintaining the naturalprocess of desquamation and/or building skin matrix components (e.g.,collagen and glycosaminoglycans). Examples of antiwrinkle and anti-skinatrophy actives include niacinamide, nicotinic acid and its esters,nicotinyl alcohol, estrogens and estrogenic compounds, or mixturesthereof.

Skin Repair Actives: Skin repair actives can be effective in repairingthe epidermal and/or dermal layer. Non-limiting examples of skin repairactives include adenosine, aloe derived lectins, ascorbyl palmitate,azaleic acid, biotin, blackberry bark extract, catecholamines,chalcones, cis retinoic acid, citric acid esters, coenzyme Q10(ubiquinone), dehydrocholesterol, dehydroepiandrosterone,dehydroascorbic acid and derivatives thereof, dehydroepiandrosteronesulphate, estrogen and its derivatives, farnesol, gingko bilboaextracts, ginseng extracts, lactate dehydrogenase inhibitors, magnesiumascorbyl phosphate, melatonin, N-acetyl cysteine, pantethine, phyticacid and its salts, retinal, retinol, retinyl acetate, retinylpropionate and vitamin K.

Lipids: Examples of suitable lipids include cetyl ricinoleate andphytanetriol.

Skin Lightening Agents: Skin lightening agents can actually decrease theamount of melanin in the skin or provide such an effect by othermechanisms. Skin lightening agents suitable for use herein are describedin EP-A-758,882 and EP-A-748,307, both of which are incorporated hereinby reference. Other skin lightening agents include arbutin, ascorbicacid, ascorbyl palmitate, azelaic acid, butyl hydroxy anisole, gallicacid and its derivatives, glycyrrhizinic acid, hydroquinine, inositolascorbate, kojic acid, niacinamide and vitamin D₃ and its analogues.

Sebum Inhibitors: Sebum inhibitors can decrease the production of sebumin the sebaceous glands. Examples of suitable sebum inhibitors includedichlorophenyl imidazoldioxolan, aluminium hydroxy chloride,corticosteroids and cucumber extracts.

Sebum Stimulators: Sebum stimulators can increase the production ofsebum by the sebaceous glands. Non-limiting examples of sebumstimulators include bryonolic acid, dehydroepiandrosterone and orizanol.

Skin Sensates: Non-limiting examples of suitable skin sensates for useherein include agents which impart a cool feel such as camphor, thymol,1-menthol and derivatives thereof, eucalyptus, carboxamides; menthaneethers and menthane esters; and agents imparting a warm feel such ascayenne tincture, cayenne extract, cayenne powder, vanillylamidenonanoate, nicotinic acid derivatives (benzyl nicotinate, methylnicotinate, phenyl nicotinate, etc.), capsaicin, nasturtium officinaleextract, Zanthoxylum piperitum extract and ginger extract, or mixturesthereof.

Protease Inhibitors: Protease inhibitors are compounds which inhibit theprocess of proteolysis, that is, the splitting of proteins into smallerpeptide fractions and amino acids. Examples of suitable proteaseinhibitors include A E COMPLEX (available from Barnet Products locatedin Englewood, N.J.), BLUE ALGAE EXTRACT (available from CollaborativeLabs Inc. located in East Setauket, N.Y.), and SEPICONTROL AS (availablefrom Seppic located in Paris, France).

Skin Tightening Agents: Examples of skin tightening agents includesodium polystyrene sulphonate, BIOCARE SA (available from Amerchollocated in Edison, N.J.) and egg albumen.

Anti-Itch Ingredients: Examples of anti-itch ingredients includeichthyol and OXYGENATED GLYCERYL TRIESTERS (available from LaboratoiresSeporgia located in Sophia Antipolis, France.)

Hair Growth Inhibitors: Suitable agents for inhibiting hair growthinclude 17 beta estradiol, anti angiogenic steroids, curcuma extract,cycloxygenase inhibitors, evening primrose oil, linoleic acid and5-alpha reductase inhibitors such as ethynylestradiol and, genistine.

Desquamation Enzyme Enhancers: These agents enhance the activity ofendogenous desquamating enzymes. Non-limiting examples of desquamationenzyme enhancers include N-methyl serine, serine, trimethyl glycine, andmixtures thereof.

Anti-Glycation Agents: Anti-glycation agents prevent the sugar inducedcrosslinking of collagen. A suitable example of an anti-glycation agentincludes AMADORINE (available from Barnet Products Distributor locatedin Englewood, N.J.).

Preferred examples of benefit agents useful herein include thoseselected from the group consisting of ascorbic acid and derivativesthereof, salicylic acid, niacinamide, panthenol, tocopheryl nicotinate,benzoyl peroxide, 3-hydroxy benzoic acid, flavonoids (e.g., flavanone,chalcone), farnesol, phytantriol, glycolic acid, lactic acid, 4-hydroxybenzoic acid, acetyl salicylic acid, 2-hydroxybutanoic acid,2-hydroxypentanoic acid, 2-hydroxyhexanoic acid, cis-retinoic acid,trans-retinoic acid, retinol, retinyl esters (e.g., retinyl propionate),phytic acid, N-acetyl-L-cysteine, lipoic acid, tocopherol and its esters(e.g., tocopheryl acetate), azelaic acid, arachidonic acid,tetracycline, ibuprofen, naproxen, ketoprofen, hydrocortisone,acetominophen, resorcinol, phenoxyethanol, phenoxypropanol,phenoxyisopropanol, 2,4,4′-trichloro-2′-hydroxy diphenyl ether,3,4,4′-trichlorocarbanilide, octopirox, lidocaine hydrochloride,clotrimazole, miconazole, ketoconazole, neomycin sulfate, theophylline,and mixtures thereof.

For cosmetic methods of treatment of the skin, hair or nails, thecosmetic benefit agent is preferably selected from anti-wrinkle andanti-skin atrophy actives, anti-acne actives, artificial tanning agentsand accelerators, emollients, humectants, skin repair actives, skinbarrier repair aids, skin lightening agents, skin sensates, skinsoothing agents, lipids, sebum inhibitors, sebum stimulators,sunscreening agents, protease inhibitors, skin tightening agents,anti-itch ingredients, and desquamation enzyme enhancers, or mixturesthereof.

Humectants

Preferred coating compositions and gel sheets comprise at least onehumectant. Humectants increase the moisturising characteristics of thedevice when applied to the target surface. Some humectants, such asglycerine, can also act as a solvent to plasticise the gel sheet.Certain humectants, such as hexylene glycol, may also contribute to theantibacterial properties of a pre-formed device of the presentinvention.

Suitable humectants for use in the present invention are described inWO98/22085, WO98/18444 and WO97/01326, all of which are incorporatedherein by reference. Preferably, the humectants for use herein areselected from glycerine, butylene glycol, hexylene glycol, panthenol,polyethylene glycol, and mixtures thereof.

In general, the coating compositions and gel sheets of the presentinvention comprise from about 1.0% to about 50%, preferably from about5% to about 45%, more preferably from about 10% to about 40% by weightof a humectant.

Emulsifiers/Surfactants

The gel sheets and coating compositions of the present inventionoptionally comprise one or more surfactants and/or emulsifiers.Emulsifiers and/or surfactants, generally help to disperse and suspend adiscontinuous phase within a continuous phase. A surfactant may also beuseful if the product is intended for skin, hair or nail cleansing. Forconvenience hereinafter emulsifiers will be referred to under the term‘surfactants’, thus ‘surfactant(s)’ will be used to refer to surfaceactive agents whether used as emulsifiers or for other surfactantpurposes such as skin, hair or nail cleansing. Known or conventionalsurfactants can be used in the composition, provided that the selectedagent is chemically and physically compatible with essential componentsof the composition, and provides the desired characteristics. Suitablesurfactants include silicone materials, non-silicone materials, andmixtures thereof.

The compositions of the present invention preferably comprise from about0.01% to about 15% of a surfactant or mixture of surfactants. The exactsurfactant or surfactant mixture chosen will depend upon the pH of thecomposition and the other components present. Preferred surfactants arenonionic.

Among nonionic surfactants useful herein are condensation products ofalkylene oxides with fatty acids (i.e. alkylene oxide esters of fattyacids); the condensation products of alkylene oxides with 2 moles offatty acids (i.e. alkylene oxide diesters of fatty acids); thecondensation products of alkylene oxides with fatty alcohols, examplesof which include PEG 40 hydrogenated castor oil, steareth-2,isoceteth-20, and oleth-20. Still other nonionic surfactants are thecondensation products of alkylene oxides with both fatty acids and fattyalcohols [i.e. wherein the polyalkylene oxide portion is esterified onone end with a fatty acid and etherified on the other end with a fattyalcohol].

Other nonionic surfactants that are useful herein are alkyl glucosidesand alkyl polyglucosides, described in more detail in WO98/18444. Stillother useful nonionic surfactants include polyhydroxy fatty acid amidesurfactants, described in WO98/04241.

Other nonionic surfactants suitable for use herein include optionallyalkoxylated sugar esters and polyesters, fatty acid amides.

Preferred nonionic surfactants are those selected from the groupconsisting of laureth-4, laureth-23, ceteareth-12, sucrose cocoate,steareth-100, polysorbate 60, PEG-60 hydrogenated castor oil,isoceteth-20, oleth-20, PEG-100 stearate, and mixtures thereof.

Other emulsifiers useful herein are fatty acid ester blends based on amixture of sorbitan or sorbitol fatty acid ester and sucrose fatty acidester, as described in more detail in WO98/22085, incorporated byreference herein.

Hydrophilic surfactants useful herein can alternatively or additionallyinclude any of a wide variety of cationic, anionic, zwitterionic, andamphoteric surfactants such as are known in the art. See, e.g.,McCutcheon's, Detergents and Emulsifiers, North American Edition (1986),published by Allured Publishing Corporation; U.S. Pat. No. 5,011,681 toCiotti et al., issued Apr. 30, 1991; U.S. Pat. No. 4,421,769 to Dixon etal., issued Dec. 20, 1983; and U.S. Pat. No. 3,755,560 to Dickert etal., issued Aug. 28, 1973; these four references are incorporated hereinby reference in their entirety.

A wide variety of cationic surfactants are useful herein. Suitablecationic surfactants for use herein are disclosed in WO98/18444.Exemplary anionic surfactants include the alkoyl isethionates (e.g.,C₁₂-C₃₀), alkyl and alkyl ether sulfates and salts thereof, alkyl andalkyl ether phosphates and salts thereof, alkyl methyl taurates (e.g.,C₁₂-C₃₀), and soaps (e.g., alkali metal salts, e.g., sodium or potassiumsalts) of fatty acids. Examples of amphoteric and zwitterionicsurfactants include betaines, sultaines, hydroxysultaines, alkylsarcosinates (e.g., C₁₂-C₃₀), and alkanoyl sarcosinates.

The gel sheets and coating compositions of the device of the presentinvention may optionally contain a silicone containing emulsifier orsurfactant. A wide variety of silicone emulsifiers are useful herein.These silicone emulsifiers are typically organically modifiedorganopolysiloxanes, also known to those skilled in the art as siliconesurfactants. Useful silicone emulsifiers include dimethicone copolyols.These materials are polydimethyl siloxanes which have been modified toinclude polyether side chains such as polyethylene oxide chains,polypropylene oxide chains, mixtures of these chains, and polyetherchains containing moieties derived from both ethylene oxide andpropylene oxide. Other examples include alkyl-modified dimethiconecopolyols, i.e., compounds which contain C₂-C₃₀ pendant side chains.Still other useful dimethicone copolyols include materials havingvarious cationic, anionic, amphoteric, and zwitterionic pendantmoieties.

Other Optional Ingredients

The devices of the present invention can comprise a wide range of otheroptional components. These additional components should bedermatologically acceptable. The CTFA Cosmetic Ingredient Handbook:Second Edition, 1992, which is incorporated by reference herein in itsentirety, describes a wide variety of non-limiting cosmetic andpharmaceutical ingredients commonly used in the cosmetic industry, whichare suitable for use in the compositions of the present invention.Non-limiting examples of functional classes of ingredients are describedat page 537 of this reference. Examples of these and other functionalclasses include: absorbents, antibiotics, anti-dandruff agents,anti-perspirant agents, antioxidants, biological additives, bleachactivators, brighteners, buffering agents, chelating agents, chemicaladditives, colorants, cosmetics, cleansers, deodorants, desquamationactives, depilatories, drug astringents, dyes, dye transfer agents,enzymes, external analgesics, film formers, fragrance components, insectrepellants, fungicides, opacifying agents, oxidative dyes, oxidisingagents, pest control ingredients, pH adjusters, pH buffers,pharmaceutical actives, preservatives, radical scavengers, skin, hair ornail bleaching agents, skin, hair or nail conditioners, skin, hair ornail penetration enhancers, stabilisers, surface conditioners, reducingagents, temperature depressors, and warmth generators.

Also useful herein are aesthetic components such as colourings,essential oils, and skin, hair or nail healing agents.

Other optional materials herein include pigments and other particulateswhich may provide visual or skin-feel benefits. Pigments suitable foruse in the compositions of the present invention can be organic and/orinorganic. Also included within the term pigment are materials having alow colour or lustre such as matte finishing agents, and also lightscattering agents. Examples of suitable pigments are iron oxides,acylglutamate iron oxides, titanium dioxide, ultramarine blue, D&C dyes,carmine, and mixtures thereof. Depending upon the type of composition, amixture of pigments will normally be used. Other particulates usefulherein include nylon-12, polymethylsilsesquioxane and dimethicone/vinyldimethicone cross polymer.

The pH of the gel sheets and coating compositions herein is preferablyfrom about 3 to about 9, more preferably from about 4 to about 8.

Methods of Producing the Gel Sheet

The gel sheets are formed by subjecting a mixture of the one or moregelling agents and hydrophilic solvent, together with any additionaladditives such as plasticisers or benefit agents, to a gelling step,thereby forming a gel sheet which is self-supporting. The nature of thegelling step depends on the nature of the gelling agent(s) used. Forexample, it may involve the addition of metal ions to cross-link apolymer solution or it may involve irradiation with ultraviolet rays toproduce a self-supporting gel.

In many cases, the gelling step is achieved via cooling. This involvesheating and mixing the solvent and gelling agent(s), and any otheroptional ingredients, to a first temperature above the gel point of themixture; placing the mixture in a suitably shaped mould; and gelling thegel-forming mixture at a second temperature, which is below the firsttemperature and at or below the gel point of the mixture to produce asolid gel sheet. Alternatively, the mixture can be made directly in amould.

In forming the gel sheet, its components can be added simultaneously orsequentially in any order. The order of adding the components may dependon the properties and characteristics thereof. Preferably, the gellingagent(s) and any benefit agents are sufficiently dissolved in thesolvent before any other components are added. By “sufficientlydissolved” is meant that the mixture appears substantially or completelytransparent. The temperature of the mixture is usually maintained abovethe gel point until all of the components are added. In some cases, itmay be beneficial to begin to lower the temperature of the mixture priorto adding certain components.

In a preferred embodiment, the gel sheet is produced via injectionmoulding. It is believed that the sheet so produced is stronger due tothe smoother finish of the surface, which provides a greater resistanceto tearing. An injection moulding process for producing a gel sheetcomprises the steps of injecting a gel-forming mixture into a suitablyshaped mould, the mixture being maintained prior to the injection stepat a first temperature above the gel point of the gel-forming mixture;and cooling the gel-forming mixture in the suitably shaped mould to asecond temperature below the gel point of the gel-forming mixture, toform a solid sheet. Prior to gelling, the mixture is kept fluid enoughto enable it to be readily supplied to a die by any conventional means,in addition to injection moulding processes. Lubricants can be added toassist in feeding the gel-forming mixture along the bore of an extrudingbarrel.

Gel-forming mixtures can be supplied to a suitably shaped mould by anywell known technique including gravity feed systems and pneumatic ormechanical injection systems. Injection moulding is the most preferredtechnique because of the fluidity and low processing temperatures of themixtures. A very wide range of moulding pressures may be employed.Generally, the moulding pressure is between about 0.1 to about 5 MPa(about 1 to about 50 atmospheres), although higher or lower pressuresmay be employed depending on the moulding technique used.

When gelling is achieved via cooling, the moulding temperature must, ofcourse, be at or below the gel point of the gel-forming mixture in orderto produce a solid sheet. The appropriate mould temperature can beachieved before, during, or after the mixture is supplied to the mould.After the sheet is moulded and cooled to a temperature below the gelpoint, the sheet is removed from the mould. The sheet requires nospecial handling during removal from the mould.

In a gel sheet which has a non-planar topography on at least one,preferably both of the first and second surfaces, the mould hascorresponding surfaces which are the negative image of first and secondsurfaces of the sheet itself. The non-planar topography is of a freelyselectable shape. If the non-planar topography has periodicity, thecorresponding mould surface has negative image of the same periodicity.

A preferred method of producing a device according to the inventioncomprises the steps of:

-   -   a) providing the solid gel sheet;    -   b) at least partially coating the first surface thereof with a        coating composition comprising at least one skin benefit agent;        and    -   c) packaging the coated gel sheet in a sealed, protective        wrapper.        The device as packaged can optionally be provided with a release        liner to help prevent the device from drying out or to improve        handling. A release liner is removed before use.

Substrates

The pre-formed devices of the present invention do not requiresupporting or strengthening by an occlusive or non-occlusive backingmaterial, often referred to as a substrate. However, a substrate,intended to be a part of the device as worn by a user, can be combinedwith the gel sheet and would confer further support or strengthening. Inaddition, substrates may also be employed to make the devices morepleasant or easier to handle in instances where the device is wet orsticky to the touch; to prevent evaporation of active ingredients; or toact as a means for adhering a device to the skin when an adhesive iscoated around its periphery. A substrate may be impregnated with, oradhered or laminated to one surface of the device. A substrate isparticularly useful when the device according has a large surface area,such as a whole face mask.

If the substrate is to be used to confer further support orstrengthening, the substrate will be sufficiently compatible with thedevice of the present invention, so as not to delaminate from thedevice. There can be difficulties in matching a substrate with the gelsheet. Combining a flexible substrate with a flexible gel does notnecessarily produce a flexible patch or mask device. Aside from theproblem of delamination, many flexible substrates often display a degreeof porosity such that the wet gel infiltrates the substrate and formsstrong gel networks within its fibres. Such networks may reduce theflexibility of the resultant device. Further, the substrate may notprovide a patch or mask device with an unobtrusive appearance on theskin, hair, or nails. This will often depend on the choice of substrateand its characteristics.

A wide variety of materials can, however, be used as the substrate. Thefollowing characteristics are desirable: (i) sufficient wet strength foruse, (ii) sufficient flexibility, (iii) sufficient loft and porosity,(iv) sufficient hydrophilicity such that the gel mixture may diffuse andinfiltrate into the substrate, (v) sufficient compatibility with themixture to prevent de-lamination, (vi) sufficient transparency ortranslucency, and (vii) appropriate size. Preferably the substrate isnon-occlusive. Suitable substrate classes meeting the above criteriainclude woven and non-woven materials; polymeric sheet materials such asformed films; and paper substrates.

Alternatively, substrate like materials may be used as a texturingsurface. If such a substrate like material is to be used as a texturingsurface, it will, preferably, delaminate easily from the device, in thesame way as a release liner.

Methods of Use

Following application of a device to a target area of the skin hair ornails, the device will generally be left on the target area for at least1 minute, preferably at least 5 minutes, it can be left on for a periodof up to 12 hours, preferably up to 3 hours, more preferably up to 1hour, though most preferably for less than 15 minutes. The device canthen be removed in one piece.

Depending on the benefit agent (or benefit agents) contained therein,the pre-formed, devices of the present invention may have at least oneof the following uses; hydrating the skin, hair or nails, smoothing finelines and wrinkles; cosmetically treating acne; firming the skin,strengthening; softening; exfoliating; improving and/or evening skintone and/or texture; skin, hair or nail lightening; tanning; reducingthe appearance of pores; absorbing or controlling secretions; protectingand/or soothing the skin, hair or nails, muscles, aches or pains;reducing puffiness, and/or dark circles; stimulating wound healing;warming, refreshing or cooling the skin, hair or nails; relievinginflammation; brightening the complexion; decongesting; reducingswelling; treating dermatological conditions; cushioning; purifying;fragrancing; reducing bacterial or micro-organism growth; healing;repelling insects; removing unwanted hair, dirt, or make-up; andcolouring or bleaching the target area to which the device is applied.Preferably, the pre-formed devices herein are cosmetically used forhydrating the skin, hair or nails; smoothing fine lines and wrinkles;and improving and/or evening the skin tone and/or texture.

EXAMPLES

The invention is illustrated by the following examples.

Gel Sheet Examples 1-4

1 2 3 4 Ingredient % w/w % w/w % w/w % w/w Agarose 0.3 0.8 1.6 1.5 Agar0.60 — — — Kelgum (Kelco)¹ — 0.5 0.8 0.75 Keltrol T (Kelco)¹ 0.2 — — —Locust Bean Gum 0.2 — — — Niacinamide — 5.0 8.0 10.0 D-Panthenol 5.0 —2.0 1.0 Glycerin 10.0 15.0 10.0 10.0 Disodium EDTA — 0.10 0.10 0.10Butylene Glycol — 5.0 — — Hexylene Glycol 3.0 — 5.0 5.0 Ethyl Paraben0.20 0.15 0.15 0.15 Water to 100% to 100% to 100% to 100% ¹Kelgum ™ andKeltrol ™ T are respectively a 1:1 mixture of xanthan gum and locustbean gum; and xanthan gum, supplied by Kelco, San Diego, CA, USA.

The polysaccharide gums are mixed with water to form a uniformlydispersed mixture (this can be facilitated by pre-dispersing thepolysaccharides in a non-solvent e.g. polyhydric alcohol) and anyadditional components are added. The mixture is heated with stirring toa first temperature above the gel point of the mixture (ca. 90° C.) tofully hydrate the polysaccharide gums. The liquid gel is then dispensedinto a suitably shaped mould. Injection moulding is the preferreddispensing method. This eliminates any defects which may be introducedby cutting the gel and so improves the robustness of the sheet.Injection moulding also allows the sheet to be readily formed into athree-dimensional structure. The liquid gel is then cooled to a secondtemperature cooler than the first temperature at or below the gel pointof the mixture (ambient temperature) to set up the gel structure. Thesheet may then be removed from the mould and coated with a coatingcompositions shown below.

If a substrate is to be used, this may be placed in the suitably shapedmould prior to dispensing the gel or it may be placed on the surface ofthe liquid gel during the cooling stage.

In some compositions, metal ions (e.g. Ca²⁺, K⁺) may be included in theformulation to increase the gel strength of the sheet. In this case, themetal ions are added in the form of an aqueous solution and are stirredinto the liquid gel immediately before the dispensing step.

The above method may be modified as necessary depending on the nature ofany additional components. For example, if non-aqueous components arepresent, the liquid gel may be homogenised immediately prior to mouldingor casting to ensure dispersion of the non-aqueous components.Similarly, if heat sensitive ingredients are incorporated, theformulation should be cooled to an appropriate temperature (dependent onthe ingredient) after the gum hydration step and the heat sensitiveingredient added at this stage.

The liquid gel may be de-gassed, e.g. by vacuum, to remove air bubblesdispersed within the liquid. This de-gassing step, if followed, would bethe final step immediately prior to dispensing the liquid gel.

Other, suitable gel sheets can be prepared by following the Examples1-15 of WO 00/06215.

Coating Composition Examples 6-10

6 7 8 9 10 Ingredient % w/w % w/w % w/w % w/w % w/w Kelgum ™ (see above)0.1 — — — — Keltrol ™ T (see above) — 0.5 0.9 — 0.8 Locust bean gum 0.4— — — — Polyacrylamide, — — —  2.75 — isoparaffin & laureth-7Niacinamide 5.0 — 8.0 3.5 10.0  D-Panthenol — 5.0 2.0 2.0 1.0 Glycerin —5.0 10.0  9.0 10.0  Disodium EDTA  0.10 0.1 0.1 0.1 0.1 Butylene glycol— 5.0 — — — Hexylene glycol — — 5.0 — 5.0 Tospearl ™ 145² — — 6.0 1.07.5 DC 2-1559 emulsion³ — — 3.0 4.0 3.0 Magnesium ascorbyl 3.0 — — — —phosphate Tocopheryl acetate 0.5 — —  0.75 — PEG-60 hydrogenated  1.50 —— — — castor oil Cetyl alcohol — — — 1.5 — Stearyl alcohol — — — 1.0 —Lonzaine ™ 16SP⁴  0.47 — — — — Tinoderm ™ E⁵ — — — — 10.0  Sucrosecocoate and — — — 1.0 — sorbitan stearate⁶ Isohexadecane — — — 2.0 —Isopropyl isostearate — — — 1.0 — SEFA cottonate — — — 1.0 — Petrolatum— — — 3.0 — Water, fragrance, to 100% preservatives²Polymethylsilsesquioxane from Toshiba ³Dimethicone, dimethiconol,laureth-4, laureth-23, and water; from Dow Corning ⁴Water and cetylbetaine from Lonza ⁵Water, tocopheryl acetate, polysorbate 80,caprylic/capric triglyceride and lecithin from CIBA ⁶Arlatone 2121 fromICI

The making method for the coating composition depends on the nature ofthe composition e.g. aqueous solution, o/w emulsion etc. and wouldfollow procedures known to those skilled in the art. The gums arepre-dispersed in a non-solvent for the gums (e.g. polyhydric alcohol)and then dispersed in a portion of the water phase. The water solublecomponents (e.g. niacinamide, panthenol) are dissolved in a portion ofthe water phase and the thickener premix is then added, with stirring,to produce a thickened coating composition. Heating may be necessary toensure complete dissolution of sparingly soluble components (e.g. ethylparaben) or to ensure complete hydration of the thickening agents.Components which are not water soluble (e.g. tocopheryl acetate) may bepre-dispersed in a solubilising agent (e.g. PEG-60 hydrogenated castoroil) prior to addition to the coating composition). Particulatematerials may be dispersed in the coating via conventional mixingtechniques.

Application of Coating to the Gel Sheet

A variety of methods are suitable for applying the coating to the gelsheet in order to form the finished device. For example, the coating maybe applied directly to the gel sheet e.g. dispensed via a pipette toprovide ‘dots’ of coating or spread with a brush to provide an uniformlayer. Alternatively, the coating may be applied using screen printingtechniques or via an extrusion process. The coating may also be appliedto the gel sheet via an indirect process. For example, the coating maybe applied to a surface of the packaging material (e.g. plastic tray,release liner sheet) and then the gel sheet is placed on top of thiscoating layer. A variety of methods may be used to apply the coating tothe packaging material. These include air atomised spraying of thecoating, dot deposition of the coating via a nozzle device or anelectrofluidic coating process of the type used in ink jet printing. Apreferred method is dot deposition of the coating composition into apackaging tray using nozzles, swirling the nozzles to provide an uniformlayer of coating, then pressing the gel sheet onto the top of thecoating composition.

The devices herein are then packaged into materials which have low watervapour permeability to minimise drying out of the device during storage.Suitable packaging for devices herein include sachets or sealed trays.Any suitable material can be used for the packaging such as plasticsmaterials and foil laminates. If the device is packaged in a sachet, itis preferably further mechanically protected prior to use. Thisprotection can be provided by a substrate or by a release liner such asa plastic film, which provides easy release for the device.

An embodiment of the device, shown in side section is shown in FIG. 1.Device 1 comprises a gel sheet 2 and coating composition 4 on a firstsurface 12 of the gel sheet. The device is generally flat with a raisedouter rim 18 which gives greater mechanical strength to the device onhandling. In plan view the device would appear broadly crescent shaped,of dimensions such that a notional rectangle of 4 cm×2 cm bounds thecrescent. The gel sheet has a second, upper surface 16 opposed to thefirst surface 12. The central, thinner portion 22 of the gel sheet hasan average thickness of 1.2 mm and is textured on the first and secondsurfaces. The texturing on the first and second surfaces is of differentpatterns and helps to reduce shine from the patch, making it lessvisually apparent in use. The texturing on the first surface 12 alsohelps the coating 4 to adhere to the gel sheet.

Methods Of Evaluation of the Devices Device Transparency

Transparency of the device is measured by assessing the visibility ofprinted text through the device. The printed text is prepared byprinting the English alphabet (capital letters) onto transparency film(Universal Office Supplies) using Microsoft Word Arial font and aLaserJet 4 Plus printer (Hewlett Packard) fitted with a black inkcartridge. Printed transparency films are prepared in font sizes rangingfrom 4 points to 28 points. The printed transparency films are then laidover white paper sheets to ensure a uniform background and all samplesassessed under normal indoor lighting conditions.

A sample of the gel of interest is moulded to produce a disc of gel witha thickness (depth) of 7 mm. This gel disc is evenly coated with thecoating composition at a rate of 0.015 gcm⁻² and placed, coated faceuppermost, onto the transparency film printed with 4 font size. Thevisibility of the printed text is assessed through the disc of gel. Ifthe text is not legible through the gel disc, the gel disc istransferred to the next largest font size print and the assessmentrepeated. This process is repeated until a font size is reached that islegible through the gel. The smallest font size legible through the gelsample is then assigned the “transparency threshold” for that device.

The preferred “transparency threshold” for the devices of the presentinvention is preferably no greater than about 10 point, preferably nogreater than about 7 point and especially preferred is no greater thanabout 4 point.

Device Flexibility

The flexibility of a device of the present invention canstraightforwardly be assessed by measuring how much the device bendsunder its own weight when it overhangs an edge. A 4 cm by 2 cmrectangular, test strip of the material used to make the device isprepared. The strip should have a rectangular cross-section of the samethickness as the average thickness of the device of interest, theaverage being weighted over the area of the largest of the first andsecond surfaces. Although, for devices of the present invention, theflexibility is predominantly determined by the gel sheet, for theavoidance of doubt the test strip should be evenly coated with thecoating composition of the device of interest at a rate of 0.015 gcm⁻².Similarly, if the device of interest includes a substrate that isintended to be part of the device as worn by a user, the test should beperformed with the substrate included. The strip, coated surfaceuppermost, is supported on a flat surface, having a rectangular edge sothat 2 cm of the 4 cm length of the strip can overhang withoutobstruction. The arrangement is shown schematically in FIG. 2. Gel strip30 (coating not shown) overhangs the vertical edge of solid support 40,whose upper surface is horizontal. The angle θ of overhang from thevertical is measured by drawing a straight line (shown as a dashed linein FIG. 2) from the tip of the gel sheet to the edge of the support.This can conveniently be done from a photograph.

The angle of overhang, θ, is the Flex Angle of the device. In generaldevices according to the invention should have a Flex Angle of fromabout 15 to about 80°, preferably from about 25 to about 75° and morepreferably from about 40 to about 60°.

1. A pre-formed device (1) for delivering benefit agents to the skin,hair or nails, the device comprising a solid gel sheet (2) havingopposed first and second surfaces (12, 16), wherein the gel sheetcomprises one or more gelling agents and at least 10% dermatologicallyacceptable hydrophilic solvent, wherein the first surface is at leastpartially coated with a discrete coating composition (14) comprising atleast one benefit agent for the skin, hair or nails.
 2. A deviceaccording to claim 1 wherein the coating composition is a liquid havinga viscosity greater than 1000 mPa·s.
 3. A device according to claim 2wherein the coating composition is in the form of an oil in wateremulsion.
 4. A device according to claim 1 wherein the hydrophilicsolvent is selected from water, ethanol, propylene glycol, glycerine,and mixtures thereof.
 5. A device according to claim 1 wherein the gelsheet is unilamellar.
 6. A device according to claim 1 wherein the gelsheet comprises at least one skin benefit agent.
 7. A device accordingto claim 1 wherein the gel sheet and the coating composition eachcomprise at least one skin benefit agent in common.
 8. A deviceaccording to claim 1 which further comprises a substrate intended to bea part of the device as worn by a user.
 9. A device according to claim 1which is packaged in a sealed, protective wrapper.
 10. A deviceaccording to claim 8 which has a transparency threshold of no greaterthan 10 point, preferably no greater than
 7. 11. A method of producing adevice according to claim 1, the method comprising the steps of: a)providing the solid gel sheet; b) at least partially coating the firstsurface thereof with a coating composition comprising at least one skinbenefit agent; and c) packaging the coated gel sheet in a sealed,protective wrapper.
 12. A method of delivering at least one cosmeticbenefit agent to the skin, hair or nails, the method comprising applyinga device according to claim 10 to a target area of the skin, hair ornails so that the coated first surface is in contact with the targetarea, and leaving the device at the target area for a period of from 1minute to 12 hours.